1. Activation of Calcium and Calmodium-dependent protein kinase
(CCaMK)
the Central regulator of plant root endosymbiosis
Sylvia Singh and Martin Parniske
presented by
Ashutosh Kumar & Bharati Singh

2. Symbiosis
A chemical communication process
Research project: plant responses to sweet talk to there microbial partner.

3. Guideline for microbial partner

4. Common symbiosis pathway
Speak, friend, and enter: signalling system that
promote beneficial symbiotic association in plants.
Nature Review .April 2013,vol-11

5. Calcium flux
Nod factor induced calcium (Ca+) in-flux followed by the efflux of
chlorine(Cl-) and potassium (k+) and alkanization of cytoplasm.
These ion movement occurred within 1 minute of adding Nod
factors and explained earlier observation of membrane
depolarization and Ph change.
The Membrane polarization was induced wide range of nod factor
concentration 10-10 to 10-7 M, with maximum induction at 10-9 and
no response at 10-11 .

6. Calcium spiking
Oscillation in cytosolic Ca have been observed following the nod factors.
The Nod factors induced ca spiking occurs with lag of approximately 10
minutes.
The ca spikes are predominantly associated with the nucleus.
Individual ca spikes have very rapid initial increase followed by a more
gradual decline.

8. Calcium and Calmodulin dependent protein kinase (CCaMK)
•Component of common symbiosis pathway
•Decoder of calcium spiking
•Positioned downstream and localised in nucleus

9. Two different binding mechanism of CCaMK
Kinase domain Calmodulin
binding domain EF hands
Ca+2
CCaMK bind ca+2 through both EF hands and calmodulin binding domain
Animal system- CaMKII

10. Regulation of CCaMK
S. singh, M. Parniske (2012), university of munich

11. Gain of function mutation of CCaMK
Threonine (T)
CCaMK – CaM binding domain – EF hands
Aspartate (D)
Isoleucine (I)
Spontaneous
nodulation
Spontaneous
nodulation
Tirichine, L., et al. (2006) Nature 441: 1153-1156
Based on model plants: M.truncatula, L.japonicus
Fully differentiated root cortical cells root nodule primordia

12. Transcriptional specificity
D.Oldroyd, (2013) ,Nature Review

13. Conclusion
• Mutants that are defective in the perception of nod factor
can no longer host the bacteria
•Genration of calcium spike signal is compulsory for
symbiosis.
•Negative regulation of CCaMk is essential to inhibit
inappropriate gene expression and organogenesis
•Genetically deregulated to trigger denovo nodule formation

14. THANK YOU